Manufacture of reinforced concrete structures.



F. DUMAS. vIVIANUFACTURE 0F REINFQRCED CONCRETE STRUCTURES,

A'PPLICATTON FILED FEB. 23| |916.

Patented 001;. 1, 1918.

2 SHEETS-SHEET 1.

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'F. DUMAS. MANUFACTURE 0F REINFORCED CONCRETE STRUCTURES.

APF'LICATION FILED FEB. 23, 1916- LQAQ.

2 SHEETS-SHEET 2.

Patented Oct. 1, 1918,

" @d F Fhl.

rnnivann DUMAs, or nonoivr, SWITZERLAND.

Specification of Letters Patent.

Patented Cet. il, 1918..

pplication led February 23, ,1916. Serial No. 79,912.

To all whom t may concern.'

Be it known that I, FnnNAND DUMAS, architect, a citizen of Switzerland,residing at Romont, Canton of Fribourg, in the Confederation ofSwitzerland, Vhave invented `certain new and useful Improvements in theManufacture of Reinforced Concrete Structures, of which the following isa specifica tion.

Hollow poles of reinforcedv concrete as usually hitherto constructedhave the disadvantage of being recessed down to their lower ends onaccount of the manufacturers being obliged to withdraw the core of themold through one of the ends' of the pole.

The hollow pole made according'to `this r invention comprises on thecontrar in at least a portion of its length, a hollow inner core or moldwhich is a permanent part of the pole, and owing to which the latter canbe made in onel piece with both its end sealed.

The said hollow inner core or mold is preferably made of hollow terracotta tiles and consists of superposed elements, the outside dimensionsof which gradually decrease upwardly while the inner diameter isconstant, and the two ends of the pole are solid and without a core.

In the drawing:

Figure 1 shows a portion of a pole, partly in elevation and partly inlongitudinal section.

Fig. 2 shows in perspective a portion of a smooth conical pole in thecourse of forma.- tion.

Fig. 3 is a cross-section at the bottom of the pole shown in Fig. 2.

Figs. 4L to 6 are cross-sections of the elements of the same pole atdifferent heights, showing the shapes of the superposed elements of theinner core of terra cotta and the corresponding changes in thereinforcements of the concrete.

Figs. 7 to 9 are cross-sections at different heights of. a pole with agrooved or fluted outer surface, and

Figs. l0 to 13 are cross-sections of various modified constructions ofthe inner hollow core and of the pole itself.

As will be seen from Fig. l, the pole comprises a solid concrete base cabove which is a hollow portion a1 tapering upwardly and wherein arearranged superposed hollow terra cotta tiles or cores b, 61, b2, b3, and

finally a solid portion a2 forming the top of the pole.

The pole is preferably molded in a vertical position in the followingmanner:

In a suitable place the first outside mold or coifer is secured to formthe solid base a and it is filled to about half the height of a withPortland cement. The lower ends of the reinforcements c are thenintroduced into theA cement, while the -upper ends are suspended to ascaffolding erected for the purpose. The molding of the base a is thencompleted. Then on the latter is placed the first tile b of the innerhollow core, around `which is arranged a second outer mold (not shown inthe drawing), and cement is introduced between this second mold'and thecore member b. Then -the operation 1s ccnl tinued by superposing newcores b and new outside molds.

This work can be facilitated as soon as the base a is formed by placingan iron tube CZ in the axial center of the latter and by fixing it in avertical position, for instance by suspension to the same scaffolding asthe reinforcements c are attached.

The cores 'b are then threaded consecutively on the tube cl in thedesired sequence, the cross-sectional shape being changed for instanceevery 3 meters. The irons or other reinforcements being held in place,the elements of outside molds or coffers are placed one by one on thetop of each other and the molding of the pole is continued in thismanner until the top portion a2 is reached. `Then the tube l iswithdrawn, and the solid top portion a2 is molded without a core. Theoutside diameter of the tube l corresponds to the smallest insidediameter of all the elements of the hollow tile core ZJ, 1, b2 as shownin dotted lines in the cross-sec tions. Those of the reinforcements 0which extend to the top will be embedded in the solid top portion a2. yThe sections of the 'hollow cores are made so as to facilitate theircentering about the tube d and to aid the insertion of thereinforcements c. It will be seen that the hollow cores b of Figs. 3 toG can be easily superposed on each other, and the same applies to thehollow cores b of Figs. 7 to 9.

The inner and outer shapes of the cores b as well as of the pole itself,may vary according to requirements. The ribs with which the said hollowcores are provided either intended to be placed so as to oii'er greaterresistance than an ordinary pole, the major axis being placed inthedirection of the greatest strain, for instance in the direction of thewind acting on an overhead electric line.

The pole, having a base of the oval crosssection shown in Fig. l0 can beof the circular cross-section shown in Fig. l1 at the top. The smallestdiameter of the core of Fig. l0 corresponds to the largest diameter ofthe core of Fig. l1.

Poles of square cross-section are preferably provided with inner ribscorrespondiiig to the outei angles, in oider to facilitate thearrangement of the reinforcements o.

i The sections of outer molds or coffers can be made for instance onemeter high, and the most suitable places for manufacturing the `polesare those having differences of level `facilitating installation ofvertical vmolds, Aand situated close to a railway station.

I claim as my invention: 1. A concrete pole comprising a core built upof a plu ality of superimposed hollow tiles having varied outerdiameters and inner diameters of substantially the same di.- mension,the said hollow tiles` being longitudinally ribbed oii their outersurfaces, and an exterior casing of concrete molded around the coie ofsuperimposed hollow tiles.

2. A concrete pole comprising a solid base at the larger end thereof, acore built up of a plurality `of superimposed hollow tiles having avaried outer diameter, and the smallest inner diameter of each 0f whichholloii7 tiles is substantially the same, the said hollow tiles beinglongitudinally ribbed on their outer surfaces, an exterior casing ofconcrete molded around the core of superim posed hollow tiles, aplurality of reinforcing bars, each reinforcing bar being molded intothe exterior concrete casing, and lying between the longitudinal ribsoii the exterior of` the hollow tiles forming the core, and a solid topmember at the smaller end of the pole.

In testimony whereof I have affixed my signature iupi'esence of twowitnesses.

v FERNAND DUMAS.

Witnesses Dr. Roi). WURTEMBERGER, Louis H. MUNIG.

Copies of this patent may be obtane for ve cents each, by addressing theCommissioner of Patents,

Washington, D. C.

